Barbecue Sauce - cooking recipe

Ingredients

medium onion
2 Tbsp. butter
2 Tbsp. vinegar
2 Tbsp. brown sugar or white sugar
4 Tbsp. lemon juice
3 Tbsp. Worcestershire sauce
1/2 Tbsp. mustard
shake of salt
1 c. ketchup
1/2 c. water
1/2 c. chopped celery

Preparation

Brown the chopped onion in 2 tablespoons butter, then mix all other ingredients and cook for 1/2 hour over medium or medium-low heat.